#include <stdio.h>

struct NullType;

template <typename T0 = NullType, typename T1 = NullType, typename T2 =NullType,           typename T3 = NullType, typename T4 = NullType, typenameT5 = NullType> struct typelist {     typedef T0 Head;     typedeftypelist<T1, T2, T3, T4, T5> Tail;     enum { length = 1 + Tail::length}; };

template <> struct typelist<NullType, NullType, NullType,NullType, NullType, NullType> {     enum { length = 0 }; };

template <typename TL, int n, bool OutOfRange = (n >=TL::length)> struct type_at {     typedef typenametype_at<typename TL::Tail, n-1>::type type; };

template <typename TL> struct type_at<TL, 0,false> {     typedef typename TL::Head type; };

template <typename TL, int n> struct type_at<TL, n,true> { };

template <typename T, typename U> struct is_same_type {    enum { value = false }; };

template <typename T> struct is_same_type<T, T> {    enum { value = true }; };

template <typename TL, typename T, int count = -1, bool equalsHead=           is_same_type<typename TL::Head, T>::value> structindex_of {     enum { value = 1 + index_of<typename TL::Tail, T,count-1>::value }; };

template <typename TL, typename T, int count> structindex_of<TL, T, count, true> {     enum { value = 0 }; };

template <typename T, typename U, int count> structindex_of<typelist<T>, U, count, false> {     enum { value =count }; };

template <typename T, typename U, bool greaterThan = (sizeof(T) >=sizeof(U))> struct type_selector {     typedef T type; };

template <typename T, typename U> struct type_selector<T, U,false> {     typedef U type; };

template <typename TL> struct largest_type {     typedeftypename type_selector<typename TL::Head, typenamelargest_type<typename             TL::Tail>::type>::typetype; };

template <typename T> struct largest_type<typelist<T>> {     typedef T type; };

int main() {     typedef typelist<int, float, double, char>types;     printf("%d\n", types::length);     type_at<types,3>::type ch = 'c';     printf("%c\n", ch);     printf("%d\n",index_of<types, unsigned>::value);     printf("%d\n",index_of<types, double>::value);     largest_type<types>::type d= 2.5;     printf("%lf\n", d);     printf("%d\n", index_of<types,largest_type<types>::type>::value); }